Smelting furnace



June 21, 1938. c. c. BERG SMELTING FURNACE Filez iAug. 10, 1937 PatentedJune 21, 1938 PATENT OFFICE SMELTING FURNACE Charles C. Berg, Spokane,Wash., assignor to Beryl Metals Company, Inc., Spokane, Wash.

Application August 10.1937, Serial No. 158,324

2 Claims. (Cl. 266-29) 7 My invention relates to improvements insmelting furnaces and has for an object to provide a smelting furnaceadapted for the reduction of ores having a multi-metallic content.

Jinother object of my invention is toprovide a smelting furnace in whichmulti-metallic ores .may be smelted and during the smelting of whichundesired metallic volatiles may be allowed to escape while thevolatiles to be saved are caused no to be mixed with air under automaticcontrol and the hot mixture passed and repassed through the smeltingores in the furnace to increase the furnace temperature and form usefulnew metallic substances.-

)5 Another object of my invention is to provide a 20 the said hotmixture of gases and air and con- A duct it to the tuyeres and alsotoretain the hot slag till is has cooled.

Another objectof my invention is to maintain the slag adjacent thetuyere openings at tem- 15. peratures above its melting point to providefor it to flow freely therefrom. I

Another object of my invention is to provide clqsable openings in thesaid annular chamber through which-to view smelting progress and 30through which to remove the said cooled slag.

Qther objects of my invention will appear as the description proceeds.

I attain these and other. objects of my invention 'with the structureand mechanism illus- 35 trated in the accompanying sheet of drawings,forming a part of this specification, in which Figure 1 is a sideelevation of my smelting furnace in section on a vertical medial plane,Fig. 2 is a front elevation of Fig. 1, Fig. 3 is a top plan 40 view ofFig. 2 and Fig. 4 is a bottom plan view of Fig. 2.

Similar characters refer to similar parts throughout. Certain parts arebroken away to show other parts hidden thereby.

parts: My furnace, as illustrated, consists of three parts; the uppertruncated cone 4, the lower cylinder '1 and the intervening truncatedcone 6, all of which are lined with the fire brick 5o 5. The open bottomof the furnace is ciosable by double, hinged doors 8, 8, having thehinges l l the pivoted latch 8 and the catch 8 with which the latchengages to retain the doors in closed position. The top opening 35 isc'losable 55 with the cover 9, lined with the fire brick l0 and Withmore particular reference to designated intake of the blower not shown.

hinged at 9. The opening 35 communicates with the s'tack-22. The loadingopening 35 is closable with the hinged door 31 which is lined with thefire brick 3B and provided with a pivoted. latch to engagearcatch on thefurnace wall for retaining the door in its closed position. A by-passopening ll extends through the furnace wall near its top and has theexternal thimble 3| with which is connected the downwarly curved pipe30. Near the bottom of the. furnace are four spaced openings Reach ofwhich, preferably, is lined with a metal thimble or bushing. Theopenings l2 serve the triple purposesof tuyeres, peep holes and slagoutlets. Close to the bottom of the furnace is the molten-metal outletl3 which communicates with the brick-lined spout 14.

The manifold chamber is annular and surrounds theinverted-truncated-conical part 6 of the furnace wall to enclose thetuyere openings. It is of triangular cross-section, preferably, and hasthe outer steel plate walls 16 and I1. Both of the walls I6 and I! arewelded to the steel plate outer wall of the furnace. Throughthe wall I6of the manifold are the four' hand holes [8, each of which is oppositeone of the tuyeres 12-. Each of the openings'l8 is closable by a door l9hinged to the manifold wall and fastenable by the pivoted latch 20'engageable by the catch 2|. of these doors is shown in its openposition in dotted lines at l 9' in Fig. 2. An opening 34 in themanifold wall It, preferably disposed midway'between two of the dooropenings [8, communicates with thepipe 33.

The furnace-is supported on four legs IS the upper ends of which areweldedto the bottom wall ll ofthe manifold. p

The sheave 23 is mounted in bearings on the stack 22 and has the chain24 placed thereon. The upper end of the chain 24 is fastened on thecover 9 and the lower part is engageable with the notched catch 25fastened on the furnace wall. A pull on the lower end of chain 24 willraise the cover 9 to its dotted-line position at 9 within the squarestack 22, thus uncovering the furnace outlet 35. By engaging the chainwith the catch 25, as shown in dotted lines at 24', the cover 9 may beretained in its open position.

The blower 26 has the pulley 2'! over which is laid the belt 28 from-apower pulley not shown. The lower end of the pipe 29 connects with theThe downwardly bent pipe '30, fromthe upper part of the furnace, isextended a short distance into the upper part of the pipe 29 which islarger than the said pipe 3|].v The relatively large annu- One lar spaceII between the pipes II and II provides for the entry of draft air intothe pipe 2! around the pipe Ill and the escape of excess furnace gases.The outlet pipe 32 of the blower It connects with the-outer end of thepipe 38, the inner end of which connects with the manifold chamber l6,ll in the opening 34.

In operation: Before charging the furnace, the molten-metal outlet II isplugged with fire clay, a covering of sand is spread over the closeddoors I, I and all of the movable parts of the furnace are in theirsolid-line positions, except the furnace-outlet cover I, which is raisedand retained in its open position at l by pulling on the chain 24 andenga ing it at its dotted-line position in the chain catch II at 24'.The charging door 31 is opened, a quantity of coke and multi-metal oresare passed through it and the door is closed. The fuel is ignited andthe blower 20 is started. The blower draws draught air through theopening I! and a small part of the products of combustion in the furnacethrough the pipe 30. But the major part of these gases escape throughthe furnace outlet fl into the stack 22.

At first the furnace heat releases the morehighly volatile metallicgases which are not desired to be retained. The progress of the processof smelting may be observed at the top of the smelter, where the coveris raised; each of the metallic contents escaping in gaseous form havingdifferent and distinct colors. when, to the expert attendant, thesecolors indicate that the more-highly volatile parts of the metals havebeen released then the speed of the blower is reduced and, the furnacecover I is closed.

The blower draws draught air through the annular opening 20-, thustending to form a vacuum at the end of pipe I, to draw the furnace gasesthrough the pipe 30 into the pipe as and force a draft at the tuyereopenings i2. Thus the furnace gases, which include the gaseous productsof combustion and the said less-highly-volatile metallic gases releasedfrom the ores, are mixed in the blower and elected through the pipes 82and 0! into the manifold Ii, ll, where they are drawn through the tuyereopenings II, l2, II, II into the combustion section of the furnace wherethe hot oxygen unites with the fuel in forced combustion.

The continuous return of the hot gases of combustion through thecombustion area of the furnace builds up the furnace temperature tillmore refractory ores are melted in this furnace than is usual incoke-fired furnaces.

The return of the said less-volatile metallic gases to the surface ofthe molten metals in the bottom of the furnace at a reduced temperatureand in the presence of carbon monoxide, which serves as a reducingagent, results in the union of these gases with the molten metals andthe form ing of a homogeneous alloy of different metals.

The continuous flow of hot gases through the tuyere openings i2maintains the contiguous slag at temperatures above its melting pointand thus it freely flows out into the manifold I, II on the bottom ofwhich it cools. Subsequently, the

hardened slag is broken up by hammer blows on the exterior of themanifold bottom and the pieces thereof are removed by hand through thehandholes.

Even with the more-volatile metallic gases eliminated from the oresbeing smelted and with the blower running at a reduced speed, there may,at times, pass out through the pipe 30 a greater flow of furnace gasesthan will be drawn through the tuyere openings l2. Then a part of thesegases will escape outward through the annular draft air inlet-ll intothe air. Meanwhile their outward movement through the said air inletwill prevent the passage of draft air into the pipe 20 and into the'fumace. The ceasing of the supply of oxygen to the fuel, thus caused,will slacken combustion and reduce the creation of furnace gases to adegree which will again allow their entire volume to be drawn into thefurnace when draft air will again be drawn through the opening 20- andnormal combustion will be resumed. Thus, even with the furnace outlet l0closed, the smelting process proceeds automatically without the use ofcontrol dampers in the said pipes and without considerable attention ofthe furnace operator.

when the smelting of the ores placed in the furnace is completed, themolten metal is drawn 01! through the spout is by unstopping the outletll.

Although the operation of a coke-fired furnace is described above, it isclear that many of the advantages gained by the particular furnaceconstruction disclosed and the smelting process which is made possiblethereby may also be ob-.

tained when an electric smelting furnace is used.

Having thus disclosed my invention, what I claim as new therein anddesire to secure by Letters Patent is,-

1. smelting apparatus including, a furnace having a by-pass opening nearits upper end and a plurality of tuyere openings near its lower end, amanifold enclosing the said tuyere openings having closable hand holeopenings, a blower, a

blower inlet pipe having an open outer end, a

furnace outlet pipe having conduit connection with the said by-passfurnace opening and extended into the said outer end of the blowerintake pipe providing an intervening annular opening, and a bloweroutlet pipe having conduit connection with the said manifold.

2. smelting apparatus including, a furnace having a closable topopening, an unclosable bypass opening below and near the said topopening and tuyere openings near the lower end of the said furnace, amanifold enclosing the said tuyere openings, a blower, a blower inletpipe having an unclosable outer end, an unclosable furnace by-passoutlet pipe extended into the said outer end of the blower intake pipeprovidingan unclosable space between them for the alternate automaticadmission of air into the blower and the exit of surplus furnace gasesinto the open air, and a blower outlet pipe having conduit connectionwith the said manifold.

CHAS. C. BERG.

